test_ssh_copy failure on riscv64 and ppc64el about kitty

[kovidgoyal]

I am afraid I dont know anything about those archs and dont really care
about them, but patches are welcome. The test failure indicates that the
python process is hanging running bootstrap.py.

[nileshpatra]

I did the following:

• Checked this on a riscv machine myself and it seems to sometimes fail, i.e. flaky test. ssh_copy is taking some time/stuck.
• Asked a risc porter and they told me it may be due to the arch being slow and hence timeout issues.

On increasing the timeout of check_untar_or_fail to 180, I did not get the failure after running the tests around 10 times. It more or less does look like a timeout pitfall but I am not 100% certain.

On trying the same build (no code changes) in our build machines 5 times, I could get a successful build and hence the test seems flaky here (possibly due to timeout).

What do you think?

[kovidgoyal]

I am fine with increasing the timeout though untarring a small file
should never take more than a few seconds.

[nileshpatra]

No wait that error comes up again when I triggered it 5 more times :(